From 49e04284db96055188f83bcc769e470f04eb9515 Mon Sep 17 00:00:00 2001
From: Dan Halbert <halbert@halwitz.org>
Date: Sat, 27 Jul 2019 14:47:58 -0400
Subject: [PATCH 1/8] discovery now done explicitly

---
 adafruit_ble/uart_client.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/adafruit_ble/uart_client.py b/adafruit_ble/uart_client.py
index dd505e6..51342b4 100644
--- a/adafruit_ble/uart_client.py
+++ b/adafruit_ble/uart_client.py
@@ -70,7 +70,9 @@ def connect(self, address, timeout):
         :param float/int timeout: Try to connect for ``timeout`` seconds.
            Not related to the timeout passed to ``UARTClient()``.
         """
-        self._central.connect(address, timeout, service_uuids_whitelist=(NUS_SERVICE_UUID,))
+        self._central.connect(address, timeout)
+        # Restrict discovery to NUS service only.
+        self._central.discover_remote_services((NUS_SERVICE_UUID,))
 
         # Connect succeeded. Get the remote characteristics we need, which were
         # found during discovery.

From 183cab6a532f6f8bbb6d0feb6415088ca300c847 Mon Sep 17 00:00:00 2001
From: Dan Halbert <halbert@halwitz.org>
Date: Sat, 27 Jul 2019 23:01:03 -0400
Subject: [PATCH 2/8] refactor advertising.py for peripheral service
 solicitation; skeletal CTS (no pairing yet)

---
 adafruit_ble/advertising.py         | 143 ++++++++++++++++++----------
 adafruit_ble/current_time_client.py |  79 +++++++++++++++
 2 files changed, 173 insertions(+), 49 deletions(-)
 create mode 100644 adafruit_ble/current_time_client.py

diff --git a/adafruit_ble/advertising.py b/adafruit_ble/advertising.py
index e507061..e4ecc54 100644
--- a/adafruit_ble/advertising.py
+++ b/adafruit_ble/advertising.py
@@ -51,6 +51,10 @@ class AdvertisingPacket:
     """Incomplete list of 128 bit service UUIDs."""
     ALL_128_BIT_SERVICE_UUIDS = 0x07
     """Complete list of 128 bit service UUIDs."""
+    SOLICITED_16_BIT_SERVICE_UUIDS = 0x14
+    """List of 16 bit service UUIDs solicited by a peripheral."""
+    SOLICITED_128_BIT_SERVICE_UUIDS = 0x15
+    """List of 128 bit service UUIDs solicited by a peripheral."""
     SHORT_LOCAL_NAME = 0x08
     """Short local device name (shortened to fit)."""
     COMPLETE_LOCAL_NAME = 0x09
@@ -131,84 +135,76 @@ def get(self, element_type, default=None):
         except KeyError:
             return default
 
+    @property
+    def length(self):
+        """Current number of bytes in packet."""
+        return len(self._packet_bytes)
+
     @property
     def bytes_remaining(self):
         """Number of bytes still available for use in the packet."""
-        return self._max_length - len(self._packet_bytes)
+        return self._max_length - self.length
 
     def _check_length(self):
-        if len(self._packet_bytes) > self._max_length:
+        if self.length > self._max_length:
             raise IndexError("Advertising data too long")
 
+    def add_flags(self, flags=(FLAG_GENERAL_DISCOVERY | FLAG_LE_ONLY)):
+        """Add advertising flags."""
+        self.add_field(self.FLAGS, struct.pack("<B", flags))
+
     def add_field(self, field_type, field_data):
-        """Append an advertising data field to the current packet, of the given type.
+        """Append byte data to the current packet, of the given type.
         The length field is calculated from the length of field_data."""
         self._packet_bytes.append(1 + len(field_data))
         self._packet_bytes.append(field_type)
         self._packet_bytes.extend(field_data)
         self._check_length()
 
-    def add_flags(self, flags=(FLAG_GENERAL_DISCOVERY | FLAG_LE_ONLY)):
-        """Add default or custom advertising flags."""
-        self.add_field(self.FLAGS, struct.pack("<B", flags))
-
-    def add_16_bit_uuids(self, uuids):
-        """Add a complete list of 16 bit service UUIDs."""
-        for uuid in uuids:
-            self.add_field(self.ALL_16_BIT_SERVICE_UUIDS, struct.pack("<H", uuid.uuid16))
-
-    def add_128_bit_uuids(self, uuids):
-        """Add a complete list of 128 bit service UUIDs."""
-        for uuid in uuids:
-            self.add_field(self.ALL_128_BIT_SERVICE_UUIDS, uuid.uuid128)
-
     def add_mfr_specific_data(self, mfr_id, data):
         """Add manufacturer-specific data bytes."""
         self.add_field(self.MANUFACTURER_SPECIFIC_DATA, struct.pack('<H', mfr_id) + data)
 
+    def add_tx_power(self, tx_power):
+        """Add transmit power value."""
+        self.add_field(AdvertisingPacket.TX_POWER, struct.pack("<b", tx_power))
 
-class ServerAdvertisement:
-    """
-    Data to advertise a peripheral's services.
+    def add_appearance(self, appearance):
+        """Add BLE Appearance value."""
+        self.add_field(AdvertisingPacket.APPEARANCE, struct.pack("<h", appearance))
 
-    The advertisement consists of an advertising data packet and an optional scan response packet,
-    The scan response packet is created only if there is not room in the
-    advertising data packet for the complete peripheral name.
 
-    :param peripheral Peripheral the Peripheral to advertise. Use its services and name
-    :param int tx_power: transmit power in dBm at 0 meters (8 bit signed value). Default 0 dBm
-    """
-
-    def __init__(self, peripheral, *, tx_power=0):
-        self._peripheral = peripheral
+class Advertisement:
+    """Superclass for common code to construct a BLE advertisement,
+    consisting of an advertising data packet and an optional scan response packet.
 
-        packet = AdvertisingPacket()
-        packet.add_flags()
+    :param int flags: advertising flags. Default is general discovery, and BLE only (not classic)
+    """
+    def __init__(self, flags=None, tx_power=None):
+        self._packet = AdvertisingPacket()
         self._scan_response_packet = None
+        if flags:
+            self._packet.add_flags(flags)
+        else:
+            self._packet.add_flags()
 
-        # Need to check service.secondary
-        uuids_16_bits = [service.uuid for service in peripheral.services
-                         if service.uuid.size == 16 and not service.secondary]
-        if uuids_16_bits:
-            packet.add_16_bit_uuids(uuids_16_bits)
-
-        uuids_128_bits = [service.uuid for service in peripheral.services
-                          if service.uuid.size == 128 and not service.secondary]
-        if uuids_128_bits:
-            packet.add_128_bit_uuids(uuids_128_bits)
-
-        packet.add_field(AdvertisingPacket.TX_POWER, struct.pack("<b", tx_power))
+        if tx_power is not None:
+            self._packet.add_tx_power(tx_power)
 
+    def add_name(self, name):
+        """Add name to advertisement. If it doesn't fit, add truncated name to packet,
+        and add complete name to scan response packet.
+        """
         # 2 bytes needed for field length and type.
-        bytes_available = packet.bytes_remaining - 2
+        bytes_available = self._packet.bytes_remaining - 2
         if bytes_available <= 0:
             raise IndexError("No room for name")
 
-        name_bytes = bytes(peripheral.name, 'utf-8')
+        name_bytes = bytes(name, 'utf-8')
         if bytes_available >= len(name_bytes):
-            packet.add_field(AdvertisingPacket.COMPLETE_LOCAL_NAME, name_bytes)
+            self._packet.add_field(AdvertisingPacket.COMPLETE_LOCAL_NAME, name_bytes)
         else:
-            packet.add_field(AdvertisingPacket.SHORT_LOCAL_NAME, name_bytes[:bytes_available])
+            self._packet.add_field(AdvertisingPacket.SHORT_LOCAL_NAME, name_bytes[:bytes_available])
             self._scan_response_packet = AdvertisingPacket()
             try:
                 self._scan_response_packet.add_field(AdvertisingPacket.COMPLETE_LOCAL_NAME,
@@ -216,12 +212,23 @@ def __init__(self, peripheral, *, tx_power=0):
             except IndexError:
                 raise IndexError("Name too long")
 
-        self._advertising_data_packet = packet
+    def add_uuids(self, uuids, field_type_16_bit_uuids, field_type_128_bit_uuids):
+        """Add 16-bit and 128-bit uuids to the packet, using the given field types."""
+        concatenated_16_bit_uuids = b''.join(
+            struct.pack("<H", uuid.uuid16) for uuid in uuids if uuid.size == 16)
+        if concatenated_16_bit_uuids:
+            self._packet.add_field(field_type_16_bit_uuids, concatenated_16_bit_uuids)
+
+        uuids_128_bits = [uuid for uuid in uuids if uuid.size == 128]
+        if len(uuids_128_bits) > 1:
+            raise ValueError("Only one 128 bit UUID will fit")
+        if uuids_128_bits:
+            self._packet.add_field(field_type_128_bit_uuids, uuids_128_bits[0].uuid128)
 
     @property
     def advertising_data_bytes(self):
         """The raw bytes for the initial advertising data packet."""
-        return self._advertising_data_packet.packet_bytes
+        return self._packet.packet_bytes
 
     @property
     def scan_response_bytes(self):
@@ -229,3 +236,41 @@ def scan_response_bytes(self):
         if self._scan_response_packet:
             return self._scan_response_packet.packet_bytes
         return None
+
+
+class ServerAdvertisement(Advertisement):
+    """Build an advertisement for a peripheral's services.
+
+    There is room in the packet for only one 128-bit UUID. Giving UUIDs in the scan response
+    is not yet implemented.
+
+    :param Peripheral peripheral: the Peripheral to advertise. Use its services and name.
+    :param int tx_power: transmit power in dBm at 0 meters (8 bit signed value). Default 0 dBm
+    """
+
+    def __init__(self, peripheral, *, tx_power=0):
+        super().__init__()
+        uuids = [service.uuid for service in peripheral.services if not service.secondary]
+        self.add_uuids(uuids,
+                       AdvertisingPacket.ALL_16_BIT_SERVICE_UUIDS,
+                       AdvertisingPacket.ALL_128_BIT_SERVICE_UUIDS)
+        self.add_name(peripheral.name)
+
+
+class SolicitationAdvertisement(Advertisement):
+    """Build an advertisement for a peripheral to solicit one or more services from a central.
+
+    There is room in the packet for only one 128-bit UUID. Giving UUIDs in the scan response
+    is not yet implemented.
+
+    :param string name: Name to use in advertisement.
+    :param iterable service_uuids: One or more services requested from a central
+    :param int tx_power: transmit power in dBm at 0 meters (8 bit signed value). Default 0 dBm.
+    """
+
+    def __init__(self, name, service_uuids, *, tx_power=0):
+        super().__init__()
+        self.add_uuids(service_uuids,
+                       AdvertisingPacket.SOLICITED_16_BIT_SERVICE_UUIDS,
+                       AdvertisingPacket.SOLICITED_128_BIT_SERVICE_UUIDS)
+        self.add_name(name)
diff --git a/adafruit_ble/current_time_client.py b/adafruit_ble/current_time_client.py
new file mode 100644
index 0000000..0430ead
--- /dev/null
+++ b/adafruit_ble/current_time_client.py
@@ -0,0 +1,79 @@
+ # The MIT License (MIT)
+#
+# Copyright (c) 2019 Dan Halbert for Adafruit Industries
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+"""
+`adafruit_ble.current_time_client`
+====================================================
+
+UART-style communication by a Central as a GATT Client
+
+* Author(s): Dan Halbert for Adafruit Industries
+
+"""
+from bleio import Peripheral, UUID
+from .advertising import SolicitationAdvertisement
+
+class CurrentTimeClient:
+    """
+    Set up a peripheral that advertises for Current Time Service,
+    and connects if found.
+
+    :param str name: Name to advertise for server. If None, use default Peripheral name.
+
+    Example::
+
+        from adafruit_ble.current_time_client import SolicitationAdvertisement
+
+        cts_client = CurrentTimeClient()
+        cts_client.start_advertising()
+        while not cts_client.connected:
+            pass
+        print(cts_client.time)
+    """
+
+    CTS_UUID = UUID(0x1805)
+
+    def __init__(self, name="CTSClient", tx_power=0):
+        self._periph = Peripheral()
+        self._advertisement = SolicitationAdvertisement(name, (self.CTS_UUID,), tx_power=tx_power)
+
+    def start_advertising(self):
+        """Start advertising to solicit a central that supports Current Time Service."""
+        self._periph.start_advertising(self._advertisement.advertising_data_bytes,
+                                       scan_response=self._advertisement.scan_response_bytes)
+
+    def stop_advertising(self):
+        """Stop advertising the service."""
+        self._periph.stop_advertising()
+
+    @property
+    def connected(self):
+        """True if a central connected to this peripheral."""
+        return self._periph.connected
+
+    def pair(self):
+        """Pair with the connected central."""
+        pass
+
+    @property
+    def time(self):
+        """Get the current time from the server."""
+        return None

From 9541ab2b59467abb3fdc283e3cb32e3f2b3575eb Mon Sep 17 00:00:00 2001
From: Dan Halbert <halbert@halwitz.org>
Date: Tue, 30 Jul 2019 14:24:17 -0400
Subject: [PATCH 3/8] working pairing non-bonding Current Time Service client

---
 adafruit_ble/current_time_client.py | 76 ++++++++++++++++++++++++++---
 1 file changed, 70 insertions(+), 6 deletions(-)

diff --git a/adafruit_ble/current_time_client.py b/adafruit_ble/current_time_client.py
index 0430ead..da4741e 100644
--- a/adafruit_ble/current_time_client.py
+++ b/adafruit_ble/current_time_client.py
@@ -28,6 +28,9 @@
 * Author(s): Dan Halbert for Adafruit Industries
 
 """
+import struct
+import time
+
 from bleio import Peripheral, UUID
 from .advertising import SolicitationAdvertisement
 
@@ -40,20 +43,26 @@ class CurrentTimeClient:
 
     Example::
 
-        from adafruit_ble.current_time_client import SolicitationAdvertisement
+        from adafruit_ble.current_time_client import CurrentTimeClient
 
         cts_client = CurrentTimeClient()
         cts_client.start_advertising()
         while not cts_client.connected:
             pass
-        print(cts_client.time)
+        cts_client.discover()
+        cts_client.pair()
+        print(cts_client.current_local_time)
     """
 
     CTS_UUID = UUID(0x1805)
+    CURRENT_TIME_UUID = UUID(0x2A2B)
+    LOCAL_TIME_INFORMATION_UUID = UUID(0x2A0F)
 
     def __init__(self, name="CTSClient", tx_power=0):
         self._periph = Peripheral()
         self._advertisement = SolicitationAdvertisement(name, (self.CTS_UUID,), tx_power=tx_power)
+        self._current_time_char = self._local_time_char = None
+
 
     def start_advertising(self):
         """Start advertising to solicit a central that supports Current Time Service."""
@@ -69,11 +78,66 @@ def connected(self):
         """True if a central connected to this peripheral."""
         return self._periph.connected
 
+    def disconnect(self):
+        """Disconnect from central."""
+        self._periph.disconnect()
+
+    def _check_connected(self):
+        if not self.connected:
+            raise OSError("Not connected")
+
     def pair(self):
         """Pair with the connected central."""
-        pass
+        self._check_connected()
+        self._periph.pair()
+
+    def discover(self):
+        """Discover service information."""
+        self._check_connected()
+        self._periph.discover_remote_services((self.CTS_UUID,))
+        services = self._periph.remote_services
+        if not services:
+            raise OSError("Unable to discover service")
+        for characteristic in services[0].characteristics:
+            if characteristic.uuid == self.CURRENT_TIME_UUID:
+                self._current_time_char = characteristic
+            elif characteristic.uuid == self.LOCAL_TIME_INFORMATION_UUID:
+                self._local_time_char = characteristic
+        if not self._current_time_char or not self._local_time_char:
+            raise OSError("Remote service missing needed characteristic")
+
+    @property
+    def current_time(self):
+        """Get a tuple describing the current time from the server:
+        (year, month, day, hour, minute, second, weekday, subsecond, adjust_reason)
+        """
+        self._check_connected()
+        if self._current_time_char:
+            # year, month, day, hour, minute, second, weekday, subsecond, adjust_reason
+            values = struct.unpack('<HBBBBBBBB', self._current_time_char.value)
+            return values
+        else:
+            raise OSError("Characteristic not discovered")
+
+
+    @property
+    def local_time_information(self):
+        """Get a tuple of location information from the server:
+        (timezone, dst_offset)
+        """
+        self._check_connected()
+        if self._local_time_char:
+            # timezone, dst_offset
+            values = struct.unpack('<bB', self._local_time_char.value)
+            return values
+        else:
+            raise OSError("Characteristic not discovered")
 
     @property
-    def time(self):
-        """Get the current time from the server."""
-        return None
+    def struct_time(self):
+        """Return the current time as a `time.struct_time` Day of year and whether DST is in effect
+        is not available from Current Time Service, so these are set to -1.
+        """
+        _, month, day, hour, minute, second, weekday, _, _ = self.current_time
+        # Bluetooth weekdays count from 1. struct_time counts from 0.
+        return time.struct_time((month, day, hour, minute, second, weekday - 1, -1))

From 4441123aad17636b8b1881dd7c1e51f624d90c6f Mon Sep 17 00:00:00 2001
From: Dan Halbert <halbert@halwitz.org>
Date: Wed, 31 Jul 2019 00:11:11 -0400
Subject: [PATCH 4/8] fix minor bugs and doc typos

---
 adafruit_ble/advertising.py         |  3 ++-
 adafruit_ble/current_time_client.py | 11 +++++------
 adafruit_ble/uart_client.py         |  1 -
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/adafruit_ble/advertising.py b/adafruit_ble/advertising.py
index e4ecc54..483fd98 100644
--- a/adafruit_ble/advertising.py
+++ b/adafruit_ble/advertising.py
@@ -29,6 +29,7 @@
 
 """
 
+import bleio
 import struct
 
 class AdvertisingPacket:
@@ -171,7 +172,7 @@ def add_tx_power(self, tx_power):
 
     def add_appearance(self, appearance):
         """Add BLE Appearance value."""
-        self.add_field(AdvertisingPacket.APPEARANCE, struct.pack("<h", appearance))
+        self.add_field(AdvertisingPacket.APPEARANCE, struct.pack("<H", appearance))
 
 
 class Advertisement:
diff --git a/adafruit_ble/current_time_client.py b/adafruit_ble/current_time_client.py
index da4741e..ccec52b 100644
--- a/adafruit_ble/current_time_client.py
+++ b/adafruit_ble/current_time_client.py
@@ -36,10 +36,9 @@
 
 class CurrentTimeClient:
     """
-    Set up a peripheral that advertises for Current Time Service,
-    and connects if found.
+    Set up a peripheral that solicits centrals for Current Time Service,
 
-    :param str name: Name to advertise for server. If None, use default Peripheral name.
+    :param str name: Name to advertise for server. If None, use default Advertisement name.
 
     Example::
 
@@ -58,9 +57,9 @@ class CurrentTimeClient:
     CURRENT_TIME_UUID = UUID(0x2A2B)
     LOCAL_TIME_INFORMATION_UUID = UUID(0x2A0F)
 
-    def __init__(self, name="CTSClient", tx_power=0):
-        self._periph = Peripheral()
-        self._advertisement = SolicitationAdvertisement(name, (self.CTS_UUID,), tx_power=tx_power)
+    def __init__(self, name=None, tx_power=0):
+        self._periph = Peripheral(name=name)
+        self._advertisement = SolicitationAdvertisement(peripheral.name, (self.CTS_UUID,), tx_power=tx_power)
         self._current_time_char = self._local_time_char = None
 
 
diff --git a/adafruit_ble/uart_client.py b/adafruit_ble/uart_client.py
index 51342b4..29c1ed4 100644
--- a/adafruit_ble/uart_client.py
+++ b/adafruit_ble/uart_client.py
@@ -40,7 +40,6 @@ class UARTClient:
       for the first character and between subsequent characters.
     :param int buffer_size: buffer up to this many bytes.
       If more bytes are received, older bytes will be discarded.
-    :param str name: Name to advertise for server. If None, use default Peripheral name.
 
     Example::
 

From 5e5c88b209204b2fbd38e9308dd27a1b65f06085 Mon Sep 17 00:00:00 2001
From: Dan Halbert <halbert@halwitz.org>
Date: Wed, 7 Aug 2019 11:13:53 -0400
Subject: [PATCH 5/8] match updated API for Characteristic properties, etc.

---
 adafruit_ble/current_time_client.py | 11 ++++++++---
 adafruit_ble/uart_server.py         | 16 +++++++++++++---
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/adafruit_ble/current_time_client.py b/adafruit_ble/current_time_client.py
index ccec52b..51269ce 100644
--- a/adafruit_ble/current_time_client.py
+++ b/adafruit_ble/current_time_client.py
@@ -36,7 +36,7 @@
 
 class CurrentTimeClient:
     """
-    Set up a peripheral that solicits centrals for Current Time Service,
+    Set up a peripheral that solicits centrals for Current Time Service.
 
     :param str name: Name to advertise for server. If None, use default Advertisement name.
 
@@ -50,7 +50,12 @@ class CurrentTimeClient:
             pass
         cts_client.discover()
         cts_client.pair()
-        print(cts_client.current_local_time)
+        print(cts_client.current__time)
+
+    To try the example above, open Settings->Bluetooth on your iOS device.
+    After the program starts advertising, ``CIRCUITPYxxxx` will show up as a Bluetooth
+    device for possible connection. Tap it, and then accept the pairing request.
+    Then the time should print.
     """
 
     CTS_UUID = UUID(0x1805)
@@ -59,7 +64,7 @@ class CurrentTimeClient:
 
     def __init__(self, name=None, tx_power=0):
         self._periph = Peripheral(name=name)
-        self._advertisement = SolicitationAdvertisement(peripheral.name, (self.CTS_UUID,), tx_power=tx_power)
+        self._advertisement = SolicitationAdvertisement(self._periph.name, (self.CTS_UUID,), tx_power=tx_power)
         self._current_time_char = self._local_time_char = None
 
 
diff --git a/adafruit_ble/uart_server.py b/adafruit_ble/uart_server.py
index d7e1c9f..4b425cc 100644
--- a/adafruit_ble/uart_server.py
+++ b/adafruit_ble/uart_server.py
@@ -28,7 +28,7 @@
 * Author(s): Dan Halbert for Adafruit Industries
 
 """
-from bleio import Characteristic, CharacteristicBuffer, Peripheral, Service
+from bleio import Attribute, Characteristic, CharacteristicBuffer, Peripheral, Service
 from .advertising import ServerAdvertisement
 from .uart import NUS_SERVICE_UUID, NUS_RX_CHAR_UUID, NUS_TX_CHAR_UUID
 
@@ -56,8 +56,14 @@ class UARTServer:
     """
 
     def __init__(self, *, timeout=1.0, buffer_size=64, name=None):
-        self._read_char = Characteristic(NUS_RX_CHAR_UUID, write=True, write_no_response=True)
-        self._write_char = Characteristic(NUS_TX_CHAR_UUID, notify=True)
+        self._read_char = Characteristic(
+            NUS_RX_CHAR_UUID,
+            properties=Characteristic.WRITE | Characteristic.WRITE_NO_RESPONSE,
+            read_perm=Attribute.NO_ACCESS, write_perm=Attribute.OPEN)
+        self._write_char = Characteristic(
+            NUS_TX_CHAR_UUID,
+            properties=Characteristic.NOTIFY,
+            read_perm=Attribute.OPEN, write_perm=Attribute.NO_ACCESS)
         self._read_buffer = CharacteristicBuffer(self._read_char,
                                                  timeout=timeout, buffer_size=buffer_size)
 
@@ -82,6 +88,10 @@ def connected(self):
         """True if someone connected to the server."""
         return self._periph.connected
 
+    def disconnect(self):
+        """Disconnect from peer."""
+        self._periph.disconnect()
+
     def read(self, nbytes=None):
         """
         Read characters. If ``nbytes`` is specified then read at most that many bytes.

From e4d6fe97c6b51e2f35f03cac54f50789ee13652c Mon Sep 17 00:00:00 2001
From: Dan Halbert <halbert@halwitz.org>
Date: Wed, 7 Aug 2019 23:48:02 -0400
Subject: [PATCH 6/8] lint; first cut at HID; not working yet

---
 adafruit_ble/advertising.py         |   1 -
 adafruit_ble/current_time_client.py |   3 +-
 adafruit_ble/hid.py                 | 269 ++++++++++++++++++++++++++++
 3 files changed, 271 insertions(+), 2 deletions(-)
 create mode 100644 adafruit_ble/hid.py

diff --git a/adafruit_ble/advertising.py b/adafruit_ble/advertising.py
index 483fd98..0e2d831 100644
--- a/adafruit_ble/advertising.py
+++ b/adafruit_ble/advertising.py
@@ -29,7 +29,6 @@
 
 """
 
-import bleio
 import struct
 
 class AdvertisingPacket:
diff --git a/adafruit_ble/current_time_client.py b/adafruit_ble/current_time_client.py
index 51269ce..65c2d34 100644
--- a/adafruit_ble/current_time_client.py
+++ b/adafruit_ble/current_time_client.py
@@ -64,7 +64,8 @@ class CurrentTimeClient:
 
     def __init__(self, name=None, tx_power=0):
         self._periph = Peripheral(name=name)
-        self._advertisement = SolicitationAdvertisement(self._periph.name, (self.CTS_UUID,), tx_power=tx_power)
+        self._advertisement = SolicitationAdvertisement(self._periph.name,
+                                                        (self.CTS_UUID,), tx_power=tx_power)
         self._current_time_char = self._local_time_char = None
 
 
diff --git a/adafruit_ble/hid.py b/adafruit_ble/hid.py
new file mode 100644
index 0000000..5195512
--- /dev/null
+++ b/adafruit_ble/hid.py
@@ -0,0 +1,269 @@
+ # The MIT License (MIT)
+#
+# Copyright (c) 2019 Dan Halbert for Adafruit Industries
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+"""
+`adafruit_ble.hid_keyboard`
+====================================================
+
+BLE HID
+
+* Author(s): Dan Halbert for Adafruit Industries
+
+"""
+import struct
+
+from bleio import Attribute, Characteristic, Descriptor, Peripheral, Service, UUID
+from .advertising import ServerAdvertisement
+
+class HID:
+    """
+    Provide devices for HID over BLE.
+
+    :param str name: Name to advertise for server. If None, use default Peripheral name.
+
+    Example::
+
+        from adafruit_ble.hid import HID
+
+        hid = HID()
+    """
+
+    HUMAN_INTERFACE_DEVICE_UUID = UUID(0x1812)
+    REPORT_UUID = UUID(0x2A4D)
+    REPORT_MAP_UUID = UUID(0x2A4B)
+    HID_INFORMATION_UUID = UUID(0x2A4A)
+    HID_CONTROL_POINT_UUID = UUID(0x2A4C)
+    REPORT_REF_DESCR_UUID = UUID(0x2908)
+    _REPORT_TYPE_INPUT = 1
+    # Boot keyboard and mouse not currently supported.
+    # PROTOCOL_MODE_UUID = UUID(0x2A4E)
+    # HID_BOOT_KEYBOARD_INPUT_REPORT_UUID = UUID(0x2A22)
+    # HID_BOOT_KEYBOARD_OUTPUT_REPORT_UUID = UUID(0x2A32)
+    # HID_BOOT_MOUSE_INPUT_REPORT_UUID = UUID(0x2A33)
+
+    #pylint: disable=line-too-long
+    HID_DESCRIPTOR = (
+        b'\x05\x01'        # Usage Page (Generic Desktop Ctrls)
+        b'\x09\x06'        # Usage (Keyboard)
+        b'\xA1\x01'        # Collection (Application)
+        b'\x85\x01'        #   Report ID (1)
+        b'\x05\x07'        #   Usage Page (Kbrd/Keypad)
+        b'\x19\xE0'        #   Usage Minimum (\xE0)
+        b'\x29\xE7'        #   Usage Maximum (\xE7)
+        b'\x15\x00'        #   Logical Minimum (0)
+        b'\x25\x01'        #   Logical Maximum (1)
+        b'\x75\x01'        #   Report Size (1)
+        b'\x95\x08'        #   Report Count (8)
+        b'\x81\x02'        #   Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+        b'\x81\x01'        #   Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+        b'\x19\x00'        #   Usage Minimum (\x00)
+        b'\x29\x65'        #   Usage Maximum (\x65)
+        b'\x15\x00'        #   Logical Minimum (0)
+        b'\x25\x65'        #   Logical Maximum (101)
+        b'\x75\x08'        #   Report Size (8)
+        b'\x95\x06'        #   Report Count (6)
+        b'\x81\x00'        #   Input (Data,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+        b'\x05\x08'        #   Usage Page (LEDs)
+        b'\x19\x01'        #   Usage Minimum (Num Lock)
+        b'\x29\x05'        #   Usage Maximum (Kana)
+        b'\x15\x00'        #   Logical Minimum (0)
+        b'\x25\x01'        #   Logical Maximum (1)
+        b'\x75\x01'        #   Report Size (1)
+        b'\x95\x05'        #   Report Count (5)
+        b'\x91\x02'        #   Output (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position,Non-volatile)
+        b'\x95\x03'        #   Report Count (3)
+        b'\x91\x01'        #   Output (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position,Non-volatile)
+        b'\xC0'            # End Collection
+        b'\x05\x01'        # Usage Page (Generic Desktop Ctrls)
+        b'\x09\x02'        # Usage (Mouse)
+        b'\xA1\x01'        # Collection (Application)
+        b'\x09\x01'        #   Usage (Pointer)
+        b'\xA1\x00'        #   Collection (Physical)
+        b'\x85\x02'        #     Report ID (2)
+        b'\x05\x09'        #     Usage Page (Button)
+        b'\x19\x01'        #     Usage Minimum (\x01)
+        b'\x29\x05'        #     Usage Maximum (\x05)
+        b'\x15\x00'        #     Logical Minimum (0)
+        b'\x25\x01'        #     Logical Maximum (1)
+        b'\x95\x05'        #     Report Count (5)
+        b'\x75\x01'        #     Report Size (1)
+        b'\x81\x02'        #     Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+        b'\x95\x01'        #     Report Count (1)
+        b'\x75\x03'        #     Report Size (3)
+        b'\x81\x01'        #     Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+        b'\x05\x01'        #     Usage Page (Generic Desktop Ctrls)
+        b'\x09\x30'        #     Usage (X)
+        b'\x09\x31'        #     Usage (Y)
+        b'\x15\x81'        #     Logical Minimum (-127)
+        b'\x25\x7F'        #     Logical Maximum (127)
+        b'\x75\x08'        #     Report Size (8)
+        b'\x95\x02'        #     Report Count (2)
+        b'\x81\x06'        #     Input (Data,Var,Rel,No Wrap,Linear,Preferred State,No Null Position)
+        b'\x09\x38'        #     Usage (Wheel)
+        b'\x15\x81'        #     Logical Minimum (-127)
+        b'\x25\x7F'        #     Logical Maximum (127)
+        b'\x75\x08'        #     Report Size (8)
+        b'\x95\x01'        #     Report Count (1)
+        b'\x81\x06'        #     Input (Data,Var,Rel,No Wrap,Linear,Preferred State,No Null Position)
+        b'\xC0'            #   End Collection
+        b'\xC0'            # End Collection
+        b'\x05\x0C'        # Usage Page (Consumer)
+        b'\x09\x01'        # Usage (Consumer Control)
+        b'\xA1\x01'        # Collection (Application)
+        b'\x85\x03'        #   Report ID (3)
+        b'\x75\x10'        #   Report Size (16)
+        b'\x95\x01'        #   Report Count (1)
+        b'\x15\x01'        #   Logical Minimum (1)
+        b'\x26\x8C\x02'    #   Logical Maximum (652)
+        b'\x19\x01'        #   Usage Minimum (Consumer Control)
+        b'\x2A\x8C\x02'    #   Usage Maximum (AC Send)
+        b'\x81\x00'        #   Input (Data,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+        b'\xC0'            # End Collection
+        b'\x05\x01'        # Usage Page (Generic Desktop Ctrls)
+        b'\x09\x05'        # Usage (Game Pad)
+        b'\xA1\x01'        # Collection (Application)
+        b'\x85\x05'        #   Report ID (5)
+        b'\x05\x09'        #   Usage Page (Button)
+        b'\x19\x01'        #   Usage Minimum (\x01)
+        b'\x29\x10'        #   Usage Maximum (\x10)
+        b'\x15\x00'        #   Logical Minimum (0)
+        b'\x25\x01'        #   Logical Maximum (1)
+        b'\x75\x01'        #   Report Size (1)
+        b'\x95\x10'        #   Report Count (16)
+        b'\x81\x02'        #   Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+        b'\x05\x01'        #   Usage Page (Generic Desktop Ctrls)
+        b'\x15\x81'        #   Logical Minimum (-127)
+        b'\x25\x7F'        #   Logical Maximum (127)
+        b'\x09\x30'        #   Usage (X)
+        b'\x09\x31'        #   Usage (Y)
+        b'\x09\x32'        #   Usage (Z)
+        b'\x09\x35'        #   Usage (Rz)
+        b'\x75\x08'        #   Report Size (8)
+        b'\x95\x04'        #   Report Count (4)
+        b'\x81\x02'        #   Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+        b'\xC0'            # End Collection
+    )
+    #pylint: enable=line-too-long
+
+    REPORT_ID_KEYBOARD = 1
+    """Keyboard device indicator, for use with `send_report()`."""
+    REPORT_ID_MOUSE = 2
+    """Mouse device indicator, for use with `send_report()`."""
+    REPORT_ID_CONSUMER_CONTROL = 3
+    """Consumer control device indicator, for use with `send_report()`."""
+    REPORT_ID_GAMEPAD = 5
+    """Gamepad device indicator, for use with `send_report()`."""
+
+    REPORT_SIZES = {
+        REPORT_ID_KEYBOARD : 8,
+        REPORT_ID_MOUSE : 4,
+        REPORT_ID_CONSUMER_CONTROL : 2,
+        REPORT_ID_GAMEPAD : 6,
+    }
+
+    def __init__(self, name=None, tx_power=0):
+        self._input_chars = {}
+        for report_id in sorted(self.REPORT_SIZES.keys()):
+            desc = Descriptor(HID.REPORT_REF_DESCR_UUID,
+                              read_perm=Attribute.OPEN, write_perm=Attribute.NO_ACCESS)
+            desc.value = struct.pack('<BB', report_id, self._REPORT_TYPE_INPUT)
+            self._input_chars[report_id] = Characteristic(
+                self.REPORT_UUID, properties=Characteristic.READ,
+                read_perm=Attribute.ENCRYPT_NO_MITM, write_perm=Attribute.NO_ACCESS,
+                max_length=self.REPORT_SIZES[report_id], fixed_length=True,
+                descriptors=(desc,))
+
+        # This is the USB HID descriptor (not to be confused with a BLE Descriptor).
+        self._report_map_char = Characteristic(
+            self.REPORT_MAP_UUID, properties=Characteristic.READ,
+            read_perm=Attribute.OPEN, write_perm=Attribute.NO_ACCESS,
+            max_length=len(self.HID_DESCRIPTOR), fixed_length=True)
+        self._report_map_char.value = self.HID_DESCRIPTOR
+
+        # bcdHID (version), bCountryCode (0 not localized), Flags: RemoteWake, NormallyConnectable
+        self._hid_information_char = Characteristic(
+            self.HID_INFORMATION_UUID, properties=Characteristic.READ,
+            read_perm=Attribute.OPEN, write_perm=Attribute.NO_ACCESS)
+        # bcd1.1, country = 0, flag = normal connect
+        self._hid_information_char.value = b'\x01\x01\x00\x02'
+
+        # 0 = suspend; 1 = exit suspend
+        self._hid_control_point_char = Characteristic(self.HID_CONTROL_POINT_UUID,
+                                                      properties=Characteristic.WRITE_NO_RESPONSE)
+
+        hid_service = Service(self.HUMAN_INTERFACE_DEVICE_UUID,
+                              tuple(self._input_chars.values()) +
+                              (self._report_map_char,
+                               self._hid_information_char,
+                               self._hid_control_point_char,
+                              ))
+        self._periph = Peripheral((hid_service,), name=name)
+        self._advertisement = ServerAdvertisement(self._periph, tx_power=tx_power)
+
+    def start_advertising(self):
+        """Start advertising the service. When a client connects, advertising will stop.
+        When the client disconnects, restart advertising by calling ``start_advertising()`` again.
+        """
+        self._periph.start_advertising(self._advertisement.advertising_data_bytes,
+                                       scan_response=self._advertisement.scan_response_bytes)
+
+    def stop_advertising(self):
+        """Stop advertising the service."""
+        self._periph.stop_advertising()
+
+    @property
+    def connected(self):
+        """True if someone connected to the server."""
+        return self._periph.connected
+
+    def disconnect(self):
+        """Disconnect from peer."""
+        self._periph.disconnect()
+
+    def _check_connected(self):
+        if not self.connected:
+            raise OSError("Not connected")
+
+    def pair(self):
+        """Pair with the connected central."""
+        self._check_connected()
+        self._periph.pair()
+
+    def send_report(self, report_id, report):
+        """Send a report to the specified device"""
+        self._input_chars[report_id].value = report
+
+
+class HIDDevice:
+    """A single HID device: keyboard, mouse, consumer control, or gamepad.
+
+    :param HID hid: The HID object used for BLE communication
+    :param int report: The report ID for this device:
+      `HID.REPORT_ID_KEYBOARD`, `HID.REPORT_ID_MOUSE`, etc.
+    """
+
+    def __init__(self, hid, report_id):
+        self._hid = hid
+        self._report_id = report_id
+
+    def send_report(self, report):
+        """Send a report, via hid"""
+        self._hid.send_report(self._report_id, report)

From 6b1dd312606ca2d2f8ee1174861d65b519db94c3 Mon Sep 17 00:00:00 2001
From: Dan Halbert <halbert@halwitz.org>
Date: Fri, 16 Aug 2019 15:20:14 -0400
Subject: [PATCH 7/8] discover_remote_services() now returns the services; no
 property needed

---
 adafruit_ble/current_time_client.py | 3 +--
 adafruit_ble/uart_client.py         | 4 ++--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/adafruit_ble/current_time_client.py b/adafruit_ble/current_time_client.py
index 65c2d34..f3c5866 100644
--- a/adafruit_ble/current_time_client.py
+++ b/adafruit_ble/current_time_client.py
@@ -99,8 +99,7 @@ def pair(self):
     def discover(self):
         """Discover service information."""
         self._check_connected()
-        self._periph.discover_remote_services((self.CTS_UUID,))
-        services = self._periph.remote_services
+        services = self._periph.discover_remote_services((self.CTS_UUID,))
         if not services:
             raise OSError("Unable to discover service")
         for characteristic in services[0].characteristics:
diff --git a/adafruit_ble/uart_client.py b/adafruit_ble/uart_client.py
index 29c1ed4..a4df20c 100644
--- a/adafruit_ble/uart_client.py
+++ b/adafruit_ble/uart_client.py
@@ -71,12 +71,12 @@ def connect(self, address, timeout):
         """
         self._central.connect(address, timeout)
         # Restrict discovery to NUS service only.
-        self._central.discover_remote_services((NUS_SERVICE_UUID,))
+        remote_services = self._central.discover_remote_services((NUS_SERVICE_UUID,))
 
         # Connect succeeded. Get the remote characteristics we need, which were
         # found during discovery.
 
-        for characteristic in self._central.remote_services[0].characteristics:
+        for characteristic in remote_services[0].characteristics:
             # Since we're remote we receive on tx and send on rx.
             # The names are from the point of view of the server.
             if characteristic.uuid == NUS_RX_CHAR_UUID:

From ab44563dae9161c268a8616bc3853792cf42b346 Mon Sep 17 00:00:00 2001
From: Dan Halbert <halbert@halwitz.org>
Date: Fri, 16 Aug 2019 18:18:01 -0400
Subject: [PATCH 8/8] Hide discovery and pairing in CurrentTimeClient

---
 adafruit_ble/current_time_client.py | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/adafruit_ble/current_time_client.py b/adafruit_ble/current_time_client.py
index f3c5866..8ea5ffe 100644
--- a/adafruit_ble/current_time_client.py
+++ b/adafruit_ble/current_time_client.py
@@ -23,7 +23,7 @@
 `adafruit_ble.current_time_client`
 ====================================================
 
-UART-style communication by a Central as a GATT Client
+Connect to a Current Time Service, as a peripheral.
 
 * Author(s): Dan Halbert for Adafruit Industries
 
@@ -43,14 +43,17 @@ class CurrentTimeClient:
     Example::
 
         from adafruit_ble.current_time_client import CurrentTimeClient
+        import time
 
         cts_client = CurrentTimeClient()
         cts_client.start_advertising()
         while not cts_client.connected:
             pass
-        cts_client.discover()
-        cts_client.pair()
-        print(cts_client.current__time)
+        # The first time a property is read, the client
+        # will do discovery and pairing.
+        while True:
+            print(cts_client.current_time)
+            time.sleep(5)
 
     To try the example above, open Settings->Bluetooth on your iOS device.
     After the program starts advertising, ``CIRCUITPYxxxx` will show up as a Bluetooth
@@ -90,15 +93,13 @@ def disconnect(self):
     def _check_connected(self):
         if not self.connected:
             raise OSError("Not connected")
+        # Do discovery and pairing if not already done.
+        if not self._current_time_char:
+            self._discover()
+            self._periph.pair()
 
-    def pair(self):
-        """Pair with the connected central."""
-        self._check_connected()
-        self._periph.pair()
-
-    def discover(self):
+    def _discover(self):
         """Discover service information."""
-        self._check_connected()
         services = self._periph.discover_remote_services((self.CTS_UUID,))
         if not services:
             raise OSError("Unable to discover service")